Improvement in lifting-jacks



JAMES DAMPMAN, OF LE BANON, PENNSYLVANIA.

Laim Patent No. 88,015, dazed Mwah 23,1869.

IMPROVEMENT IN LIFTING'JACKS.

' **Qbh* The Schedule referred to in these Letters Patent and making part of the same.

To all whom it may concem Be it known that I, JAMES DAMPMAN, of Lebanon, in the county ofLebanon, and State of Pennsylvania, have invented a. new and improved Lifting-J ack; and I do hereby declare that the following is a full, clear, and exact description thereof, which will enable others skilled in the art to make and use the same, reference being had to the accompanying drawings, forming part of this specification, in which- Figure 1 is a front view of my improved lifting-jack.

Figure 2 is a vertical longitudinal section ofthe same, taken through the line w x, fig. 1.

Similar letters of reference indicate corresponding parts.

My invention has for its object to furnish a simple, convenient, and effective lifting-jack, by means of which Weights may be quickly and readily raised and held till secured or made ready to be` again lowered to their places; and

It consists in the construction and combination of the various parts, as hereinafter more fully described.

' A is the frame, or standard,'of the machine, consisting of two side bars, or uprights, placed parallel with each other, and secured, at their ends, to two filling-blocks, by which they are held in their proper relative positions.

The side bars, or uprights, of the standard A, are each grooved longitudinally, upon their inner sides, with two'parallel grooves, as shown in fig. 2.

Two rows of holes are formed in the standard A, in the line of the grooves in the side bars of said standard, as shown in iig. 2, to receive-the fulcrum and holding-pins, as hereinafter described.

B is a block, having a projecting hook, or shoulder, formed upon the lower part of its forward side, to receive the weight to be raised.

To the sidesoil the block B are attached the arms of the yoke C, which fit into the grooves of the side bars of the standard A, and keep the block B in proper position. while moving up and down.

To the' arms of the yoke O, just above the upper end of the lifting-block B, is pivoted the lower end of the link, or connecting-block, D, tothe upper end of which is pivoted the forward end of the lever E, which passes back between the side bars of the standard A, and is pivoted to ears formed upon or attached to the fulcrum-block F, which slides up and down between the side bars of the standard A, and is formed with side tongues, fitting intothe rear grooves in the side bars of lthe said standard A, so as to keep the said block in proper position as it moves up and down. i

The upper end of the fulcrum-block Fis so formed,

as shown in iig. l, as to limit the movement ofthe lever E. 4

G is the fulcrum-pin, which is placed in the rear row of holes in the standardA, to support the fulcrumblock F, while operating the lever E, to raise the weight.

H is the liftingor supportingfpimwhich is placed in the front row of holes in the standard A, to support the lifting-block B, and, with it, the weight being raised, while shifting the position ofthe fulcrum-block F and fulcrum-pin G, to obtain a fresh purchase for the lever E.

I is a stud, passing down through a hole in the upper filing-block, directly over the lifting-block B,and having a screw-thread cut upon its lower end, which screws into a hole in the upper, or bent part of the yoke C.

Upon the upper end of the stud I is formed a square head, s0 that it may be taken hold of with a Wrench, to screw the said stud into and out of its place.

This stud is designed for use in raising weights which are too high to be reached by the lifting-block B, and,`

when not required for use, may be taken out and laid aside.

The side bars of the stand, or frame, A, may be strengthened .by transverse bolts, or rivets, a', passing through them, as shown in figs. 1 and 2.

The lever E may, if desired, befmade in two parts, connected with each other by means of a socket formed in the end of the one part, and a tenon formed in the end of the other part, as indicated in dotted lines in fia. 2.

bHaving thus described my invention,

I claim as new, and desire to secure by Letters Patent- The combination of the grooved and perforated standard A, yoke O, connecting-link D, lever E, fulcrum-block F, and pins G H, with the lifting-block B and stud I, substantially as described, for the purpose specified.

. JAMES DAMPMAN. Witnesses:`

J. H. WALT'Z, A. S. LIGHT. 

